:root {
    --main-color: #ffc600
}

html {
    font-size: 16px;
    font-family: sans-serif;
    color: #fff;
    box-sizing: border-box;
}

body {
    z-index: 2;
    background-image: url(./source/image/concert-drum-kit.jpg);
    display: flex;
    width: 100%;
    height: 100vh;
    justify-content: center;
    align-items: center;
}

body, html {
    margin: 0;
}

.keys {
    display: flex;
    flex-direction: row;
    gap: 1rem;
}

.key {
    min-width: 6rem;
    padding: 1rem;
    border: 3px solid black;
    border-radius: 1rem;
    text-align: center;
    background-color: rgba(0, 0, 0, .5);
    transition: all .05s linear;
}

.key.playing {
    background-color: rgba(255, 198, 0, .6);
    border-color: var(--main-color);
    transform: scale(1.1);
}

.key > kbd {
    font-size: 1.5rem;
}

.key > .sound {
    display: block;
    margin-top: 1rem;
    color: var(--main-color);
    font-weight: bold;
}

